EP0825450A2 - Dispositif de blindage électromagnétique pour appareils de résonance magnétique nucléaire - Google Patents

Dispositif de blindage électromagnétique pour appareils de résonance magnétique nucléaire Download PDF

Info

Publication number
EP0825450A2
EP0825450A2 EP97113891A EP97113891A EP0825450A2 EP 0825450 A2 EP0825450 A2 EP 0825450A2 EP 97113891 A EP97113891 A EP 97113891A EP 97113891 A EP97113891 A EP 97113891A EP 0825450 A2 EP0825450 A2 EP 0825450A2
Authority
EP
European Patent Office
Prior art keywords
shielding structure
elements
closing
cavity
opening
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP97113891A
Other languages
German (de)
English (en)
Other versions
EP0825450B1 (fr
EP0825450A3 (fr
Inventor
Alessandro Carrozzi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Esaote SpA
Original Assignee
Esaote SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Esaote SpA filed Critical Esaote SpA
Publication of EP0825450A2 publication Critical patent/EP0825450A2/fr
Publication of EP0825450A3 publication Critical patent/EP0825450A3/fr
Application granted granted Critical
Publication of EP0825450B1 publication Critical patent/EP0825450B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/42—Screening
    • G01R33/422—Screening of the radio frequency field

Definitions

  • the invention relates to an electromagnetic shielding device for nuclear magnetic resonance apparati, which apparati have a cavity with at least one or more openings for introducing the body or the part thereof under examination, and which cavity is defined by at least one magnet for generating a static field, one or more coils for generating a magnetic field gradient, one or more coils for generating spin exciting radio-frequency pulses, and one or more coils for receiving the echo signals generated by spin excitation inside the body or the part thereof under examination, whereas the transmitting and receiving coils are contained in an electromagnetic shielding structure, made of conductive material, which is open at the openings of the measurement cavity, said shielding structure being connected or connectable to ground, there being provided removable shielding elements, electrically connectable to the shielding structure, and in such a shape as to prevent or reduce the infiltration of electromagnetic noise from the outside to the inside of the cavity, in an amount affecting the reception of echoes and the transmission of excitation pulses, which elements are meant to close entirely or only partially, the shielding structure at the opening/s for
  • US 4,725,781 discloses such a shielding device.
  • the shielding device is provided as combined with a nuclear magnetic resonance image detecting apparatus, of the type adapted to contain, in its cavity, only one body part.
  • the cavity which is substantially defined in shape by the shape of the coil of the magnet for generating the static field is tubular and open at its ends.
  • the stationary part of the electromagnetic shield is stably integrated into the magnetic structure of the apparatus, and is positioned radially inside the coils for generating the gradient field, and radially outside the coils for transmitting nuclear spin exciting pulses.
  • the electromagnetic shield is also open, and may be entirely or partially closed by electrically conductive elements, which may be removably applied at the ends of the cavity and electrically connected to the stationary part of the shield.
  • the open end of the cavity, through which no body part is intended to pass, may be completely closed.
  • the end of the cavity through which the body part is intended to enter into the detection area is only partially closed by a removable shielding element, with an opening which is reduced, according to the body size, with respect to the span of the opening of the cavity.
  • the shielding means are in contact with the body or the part thereof passing through them, to penetrate the cavity.
  • the shielding is not aimed at preventing noise infiltrations, but at ensuring a higher concentration of the field lines of the RF transmitting and/or receiving coils. Particularly, no emphasis is placed on keeping the open areas of the detection cavity far from the image zone, that is from the receiving coil, on the contrary, in order to obtain the purposes stated in the document, the effectiveness of the shielding increases as the inner volume of the shield is decreased, i.e. as the latter approaches the image zone. Moreover, this type of shielding is absolutely ineffective against electrical noise.
  • Appearance and comfort are also important for the patient who should not be shocked during his treatment, and especially should not be frightened but reassured by the appearance of the apparatus.
  • the article entitled "Shielded solenoidal probe for in vivo NMR studies of solid tumors" by Th. C. NG, J. D. Glickson, published in "Magnetic Resonance in Medicine", vol. 2, 1985 provides, for the study of cutaneous and subcutaneous tumors, the introduction of a mouse into a metal cylinder connected to ground, which cylinder has an opening with a variable span, from which a part of the tumor tissue to be examined is made to protrude.
  • the combination of the animal and the shielding cylinder is inserted into the cavity and into the area being relevant for nuclear magnetic resonance image acquisition.
  • the shielding is used to eliminate the echoes coming from the innermost parts of the body of the animal with respect to the outer areas, having the tumor cells to be examined.
  • Electromagnetic noise which may eventually affect the quality of the acquired image and which come from outside are not a problem. The reason is that the tested element, that is the animal, may be completely introduced into the cavity for image detection in such a distant position from the openings that it is anyway not much exposed to electromagnetic noise.
  • the invention is based on the problem of providing an electromagnetic shielding device for nuclear magnetic resonance apparati, particularly for apparati being meant to detect images of predetermined body parts which, thanks to simple and cheap expedients, reduce or eliminate both magnetic and electrical noise coming from outside, while having a construction providing a simple, comfortable and reliable use thereof by the medical staff, and being also comfortable, non-traumatic and visually reassuring for the patient.
  • An additional object of the invention is to provide such shielding devices so that they may be used in the same way or with negligible differences in nuclear magnetic resonance image detection apparati having more than two opposite openings and a detection cavity whose shape is not closed in itself, especially in apparati having a C-shaped geometry.
  • the invention achieves the above objects by providing a device as described hereinbefore, in which the removable elements for closing the shield at the opening/s of the detection cavity, which elements are provided with passage openings for body parts, may be fastened or compressed against said body parts in such a way as to close the opening and generate a safe low-impedance electrical contact between the body and said elements for closing the shield and the shield itself.
  • the body of the patient may be connected to the shield and thus to ground, and as a result the eventual electrical noise is also neutralized.
  • a band may be fastened around the body part, said band being made of an electrically conductive material both on the inner surface being in contact with the skin and on the outer surface being fastened and compressed by the corresponding element for closing the open side of the detection cavity, said element being in turn connected to the stationary part of the shield.
  • the band which is fastenable around the body has the advantage of offering a larger surface for contact with the skin, helping to reduce the resistance of the electrical contact area. This allows to exceed and maintain the values of shield-skin contact resistance within mean values that may be accepted for the desired shielding effects, regardless of the different characteristics of electrical conductivity of the skin.
  • the elements for closing the shield which are provided with openings for the insertion of the body, are given a certain predetermined length, between the end being attached to the shielding structure and the end being in contact with the body, in such a way as to keep the opening of the shielding structure as far as possible from the image zone.
  • the elements of the shield which may be removably mounted at the opening/s are made of flexible and deformable elements having, as a conductive material, at least one layer of electrically conductive metal wire mesh, for example made of copper, or similar.
  • a metallized fabric or sheets made of other conductive materials, preferably having suitable characteristics of deformability and flexibility, such as, for example, aluminium sheets, or similar.
  • the elements for closing the open sides of the shield are advantageously made of sleeves of flexible material and with a truncated cone shape, which are open at the two bases of the truncated cone, wherein there are also provided means for removable contact on the one side with electrical connectors to the stationary shield and on the other side with the body of the patient, said means being electrically connected to a layer of mesh made of an electrically conductive material.
  • the sleeve has a coulisse in which a fastening string is made to slide. This ensures a perfectly closed form of the truncated cone-shaped sleeve.
  • the means for mechanical/electrical connection may be made of removable snap coupling elements, such as snap fasteners, made of conductive material, or of means as the so-called "Velcro", having conductive characteristics, which are electrically connected, on the sleeve, to the conductive layer of mesh, whereas in the detection area, they form a crown extending along the edge of the opening/s of the detection area, each snap fastener, or other means, being electrically connected to the corresponding end of the stationary part of the shield.
  • removable snap coupling elements such as snap fasteners, made of conductive material, or of means as the so-called "Velcro", having conductive characteristics, which are electrically connected, on the sleeve, to the conductive layer of mesh, whereas in the detection area, they form a crown extending along the edge of the opening/s of the detection area, each snap fastener, or other means, being electrically connected to the corresponding end of the stationary part of the shield.
  • the sleeve may have a coulisse with a fastening string held therein, like on the side connected to the body, while in this case, the stationary shield ends with an annular flange, having an L-cross section, which projects out of the machine case, and surrounds the opening/s of the detection cavity.
  • the sides of the fastening flange of the sleeve, being accordingly polygonal, are advantageously arched, in an outwardly convex sense, that is in the direction of the surface being in contact with the coulisse of the sleeve.
  • the element for closing said open side/s is made in the form of a continuous curtain, and may be fixed in such a way as to be in electrical contact with the corresponding parts of the stationary shield, both thanks to the flange, by radial fastening, and by means of snap fasteners, as previously described. Even in this case, the closing elements may be made of the same flexible material as the one forming the sleeve.
  • the elements for closing the stationary electromagnetic shield at the open side/s of the detection cavity, or at least at part of the open side/s of the detection cavity consist of a plurality of preshaped compressible stuffed elements, like cushions or similar, which are externally coated with a layer of an electrically conductive material, for example of the same copper mesh as provided inside the sleeve, and are inserted through slight forcing between the body part, passing through or substantially filling the open side/s and the ends of the stationary shield, at the edge of said side/s.
  • the contact with the body is of the compression type, like in the sleeve of the previous example.
  • the contact with the ends of the stationary shield at the opening/s of the detection cavity is obtained through compression contact surfaces, or through means like snap fasteners, or yet through means made of tapes as the so-called "Velcro", made of a conductive material, with one part thereof being associated to the cushions, and the other being provided along the delimiting edge of the opening/s of the detection cavity, and being in electrical contact with the corresponding end of the stationary shield.
  • cushions being at least partially inflatable and removably fixed at the opening/s of the detection cavity, and in a condition of electrical contact with the stationary shield, in the same manner as previously described.
  • the cushions may be pre-shaped. Therefore, for example in the case of a cavity being defined by a tubular wall, the cushions may be shaped accordingly, either of one single piece or in composable sectors, and with facing surfaces for mutual electrical contact.
  • the combined use of the solutions disclosed above allows to obtain an effective shielding even with magnets having C-cross sections, being open on three sides.
  • These magnets are designed to perform RMN analyses also in the shoulder area.
  • the patient is lying on an examination table, which is movable relative to the magnet bringing the shoulder into the relevant area of the detection cavity.
  • the means provided in this embodiment for closing the stationary shield at the open side/s of the detection cavity are on the examination table itself, and the patient rests upon them.
  • the electrical contact with the corresponding end of the stationary shield may be obtained through contacts passing through the examination table itself.
  • the cushion is fixed to the upper side of the examination table and is connected to connectors, for example snap fasteners or other contacts provided on the upper side of the examination table, whereas said contacts are connected to the stationary shield, in the operating position, by wiping contacts, projecting out of the lower side of the examination table, and interacting with contact plates provided along the edge of the opening/s of the detection cavity, said plates being also in electrical contact with the stationary shield.
  • connectors for example snap fasteners or other contacts provided on the upper side of the examination table
  • the examination table has apertures, for the insertion of the extensions of the cushion/s, which extensions are connected to the stationary shield, by removable coupling connectors, for example like the snap fasteners described above.
  • the inner shield may be made in different manners, particularly of a continuous conductive sheet, supported by a substrate of rigid insulating material.
  • the shield in order to prevent that the free circulation of currents induced by the magnetic noise in the electromagnetic shield negatively affects the variation speed of the field of the gradient coils, the shield may be made of a plurality of sectors, having the form of partial-surface foils, being side-by-side and slightly spaced, whereas the single sectors are connected through condensers with a predetermined capacitance, based on the working frequency of the machine, so that the total capacitance between one sector and the one next to it is of a few pF/cm of length of the adjacent sides, at a frequency of about 8 MHz.
  • the shield offers a continuous action for radio-frequency magnetic noise, that is included in the range of transmitting and receiving frequencies.
  • the condensers when properly dimensioned, do not act as obstacles, and so the shielding is operating.
  • the currents induced by the flow variation when the field is generated or disactivated, are effectively blocked by the capacitive connections between the individual foils, and are prevented form circulating freely.
  • the shielding action does not occur, and the shield is perfectly transparent to the field generated by the gradient coils.
  • This construction may eventually be extended to the elements for closing the shield on the open sides of the cavity.
  • the foils of which the sectors are made may form the condensers, by partially overlapping the foils of two adjacent sectors, and by interposing a suitable dielectric between them.
  • the capacitance of the capacitive junction between two sectors depends on the overlapping surface and on the type of dielectric.
  • the invention relates to other improvements, which form the subject of the dependent claims.
  • a nuclear magnetic resonance image detection apparatus comprises a magnet for generating a static field 1, a gradient coil 2, one or more coils 3 for transmitting radio-frequency spin exciting pulses, and one or more coils 4, for receiving echoes from nuclear spins.
  • the magnet for generating the static field 1 has an annular shape, and defines, together with the other coils, a tubular detection cavity 5, in which the receiving coil/s 4 are held and into which the body K or the part thereof to be examined are inserted. The whole is enclosed in a protecting case 6, defining the inner wall of the tubular cavity 5.
  • the transmitting coils/s 3 are disposed inside the gradient coil 2 and the receiving coil/s may be generally removably mounted therein.
  • an electromagnetic shield 7 which extends substantially concentrically with respect to the wall delimiting the detection cavity 5, entirely enclosing it.
  • the shield is generally made of a sheet of an electrically conductive material 107, which is attached, for example glued, to the inner surface of a supporting panel, which is accordingly folded or deformed in a cylindrical, tubular shape, and is made of plastic or of another insulating material 207.
  • the shielding sheet 107 is connected to ground, with its edges at the open ends of the detection cavity 5 being connected to a respective outer annular flange 8, having a L-shaped section, with respect to an axial plane.
  • the said annular flange 8 forms an element for mechanical removable attachment and electrical connection between the shielding sheet 107 and an element for closing the shield on the open ends of the latter, at the openings of the shielding cavity 5.
  • Said closing elements 9, 10 may be fixed to the flange 8. They may be made, as required by different cases, of a cover or wall of which the side 109 being in contact with the flange 8 is made of an electrically conductive material, such as a metal wire mesh, whereas externally it is made of an insulating fabric layer, such as synthetic fibers, or similar, said cover 9 entirely closing the corresponding opening of the detection cavity 5, or of a substantially truncated cone-shaped sleeve 10, with a predetermined length, which has an opening for inserting a body part, eventually projecting out of the detection cavity 5.
  • the two elements 9, 10 are interchangeable and allow to close the electromagnetic shield either completely or leaving an aperture for the insertion of the body.
  • the body part under examination is the hand, and so the flanges 8 have, on one side the cover 9, and on the other the sleeve 10 mounted thereon. If a knee were to be examined, for example, then another sleeve 10 should be provided instead of the cover 9.
  • the cover 9 may be made in the form of a dome or cap, so as to form a compartment for holding the end portion of the body or adhering thereto, which projects to a predetermined small extent out of the associated opening of the detection cavity 5, thus adhering to the form of the body K, without having to break the shielding structure, like for the sleeve 10.
  • the sleeve 10 has different functions. First, it reduces the span of the open side of the cavity 5 to which it is associated. Further, it keeps the position of the aperture far from the area of the cavity in which the echoes of nuclear spins are detected, and furthermore it is provided with fastening means around the corresponding body part K, which projects out of the detection cavity 5.
  • the sleeve has, internally, an electrically conductive fabric layer 110, at least partially made of metal wires, whereas, externally, it is provided with an insulating fabric layer 210, for example made of synthetic fibers.
  • the two fabric layers 110, 210 are glued or anyway attached in a different manner, eventually sewed.
  • the two fabrics are folded in such a manner as to form a coulisse for the passage of a string 11 for fastening, on one side the L-shaped flange 8, and on the other side, the body of the patient.
  • the two fabrics are outwardly folded together, so that the coulisse has the electrically conductive fabric 110 on the outside, allowing to generate the electrical contact between the sleeve 10 and the flange and the sleeve 10 and the body K. This is also valid for the cover 9, but only as regards the flange 9.
  • the sleeve 10 has also ventilation apertures 310, allowing for a certain amount of air circulation, thus preventing an excessive perspiration of the patient.
  • the ventilation apertures 310 are delimited by slots 12, which are made of an electrically conductive material at least on the side of the electrically conductive fabric 110. Moreover, as shown in figure 2, the slots 12 may bear a gauze 112 extending on the span of the ventilation aperture, which may also be made of an electrically conductive material.
  • the sleeve 10 is not directly fastened on the body K of the patient, but on an openable band 13, also preferably made of electrically conductive fabric, both on the inner side, in contact with the skin, and on the outer side, in contact with the sleeve.
  • the band 13 is open, and has closing means 113 at its ends, for example of the type known as Velcro, or similar.
  • the band 13 has a predetermined width, based on the conditions for ensuring a minimum resistivity of contact between the skin and the band, through different physiological conditions.
  • the band 13 may be also provided with different means providing contact with the sleeve 10, for example also means of the snap fastener type (not shown), which snap fasteners are distributed along the extension of the corresponding end of the sleeve 10, and, in a substantially coincident position, along the band itself, and which snap fasteners are made of an electrically conductive material, and are connected, both mechanically and electrically, to the electrically conductive fabric layers of said two parts.
  • the snap fastener type not shown
  • the detection cavity 5, and thus the flanges 8, which form the extension of the stationary part of the shield 7, may have a polygonal, for example rectangular, cross section.
  • the flanges 8, also rectangular have sides which are not perfectly straight, but slightly outwardly arched, and rounded edges. This allows to obtain a contact, along the whole extension of the sleeve 10, with the flange 8, and to avoid a fastening tension, exerted with sharp edges and perfectly straight sides, which causes insufficiently stable contacts along the whole extension of the flange and of the corresponding coulisse for fastening the sleeve 10.
  • the stationary shield 7 is not composed of a continuous shielding foil, but of a plurality of spaced sectors 107', connected by condensers 14.
  • the spacings between the individual foils 107' have been exaggerated.
  • the foils extend for the whole axial length of the shielding sheet.
  • This embodiment allows to prevent the shield 7 from taking effect also against the magnetic field variations generated by the gradient coil 2.
  • the gradient coil 2 is not constantly active, but is alternately activated. When it is activated, the field grows progressively and, in the shield 7, the flow variation generates circulating currents which partially shield the gradient field, i.e. more precisely, which delay the attainment of the operational value.
  • the capacitance of condensers may be chosen in such an amount as to allow for induction, in the shield, of circulating currents due to a noise which is relevant for transmission and reception, and as to be an obstacle to the generation, in the shield 7, of shielding circulating currents, due to the variation of the magnetic flow, when the gradient coils are activated.
  • the ideal capacitance is found to be of about 10 pF/linear cm of length of the facing edges of two adjacent foils 107', at frequencies of about 8 MHz.
  • the L-shaped flange 8 is made of an annular supporting element 108', made of an insulating material, and bearing, on its outer surface, a crown of L-shaped electrical contacts 208, each for one of the foils 107', and in electrical contact therewith.
  • a crown of strips made of electrically conductive fabric 110 which are spaced and connected by condensers 14, like the shield 7'.
  • Figures 6, 7, and 8 show the structure of the magnet and of the cavity 5 in a different nuclear magnetic resonance image detection device.
  • the geometry of the magnet is C-shaped, so the cavity 5 is open on three sides.
  • the magnet for the magnetic field 1' is C-shaped, and so is the electromagnetic shield 7''.
  • each curtain has at its opposite ends a row of first metal, electrically conductive parts of snap fasteners, referred to as 16, with a row of second parts of snap fasteners 17 corresponding thereto along the edges of the openings of the detection cavity 5.
  • the first parts of the snap fasteners 16 are in electrical contact with the electrically conductive fabric forming the curtains 18, whereas the second parts are in electrical contact with the corresponding edge of the shield 7''.
  • the curtains have an opening for the introduction of a limb into the cavity 5, which opening is or may be removably associated to a sleeve, being substantially like the sleeve 10, at least in the terminal portion providing contact with the body and as for the truncated cone shape.
  • the shield 7'' may be closed on all sides of the cavity 5, around body parts inserted therein, thus obtaining the advantages of the previous embodiment.
  • bands may be used to improve the electrical contact with the body.
  • the curtains 18 may no longer be advantageously used, as combined with sleeve-like elements, to effectively close the shield.
  • the body K of the patient is partially outside the cavity, practically on all open sides thereof, and therefore no sleeve-like elements as those used for the hand or the leg, may be provided.
  • cushion elements 20 are internally made of an elastic material, such as sponge rubber, or other foamed materials, and are externally coated with an electrically conductive mesh, for example the same fabric 110 as that forming the inner layer of the sleeve 10. Said elements are forced between the patient and the plates 21 or the fixtures 16, thus generating an electrical contact between the body of the patient and the shield 7''.
  • an elastic material such as sponge rubber, or other foamed materials
  • the areas of the openings of the cavity 5, which are left completely clear of the body, may be closed using the curtains 18, which may have means for electrical connection to the cushions.
  • the means for automatic fastening and electrical connection to the shield 7'' may be made, again, of first and second parts of automatic fasteners 16, 17, the ones attached to the shield 7'' and the others to the cushions 20.
  • the electrical connection between the body of the patient and the shield 7'' may no longer be established, unless through the examination table 24.
  • the lower cushions are associated to the examination table 24 and connected to one or more wiping contacts 25 borne by it, and projecting out of its lower side, which wiping contacts 25 may be connected to the cushions by means of snap fasteners, like in previous cases, or by other means and interact with contact plates 26, connected to the ends of the shield 7'' in the corresponding position.
  • the examination table has passage slots 124, through which the cushions 20 are connected to contact plates or to second parts of snap fasteners, being associated or electrically connected to the shield 7'', through extensions which penetrate the slots 124 and bear, in predetermined positions, the first parts of the snap fasteners.
  • electrical noise is removed by connecting the shield to ground, thereby the electromagnetic noise picked up by the body of the patient is eliminated.
  • the strictly magnetic noise is eliminated by reducing the shield and by closing it around the detection cavity 5, as well as by keeping the eventual openings, which are also reduced, far from the area of the detection cavity, in which the examination takes place.
  • the invention is not limited to the embodiments described and illustrated hereinbefore, but may be greatly varied, especially as regards construction.
  • the embodiment relating to the division of the conductive sheet into more adjacent sectors, connected by condensers may be also extended to the shield associated to the C-shaped magnet.

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Epidemiology (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
EP97113891A 1996-08-22 1997-08-12 Dispositif de blindage électromagnétique pour appareils de résonance magnétique nucléaire Expired - Lifetime EP0825450B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITRM960591 1996-08-22
IT1996RM000591A IT1306601B1 (it) 1996-08-22 1996-08-22 Disposizione di schermaggio elettromagnetico per apparecchiature arisonanza magnetica nucleare

Publications (3)

Publication Number Publication Date
EP0825450A2 true EP0825450A2 (fr) 1998-02-25
EP0825450A3 EP0825450A3 (fr) 1999-12-29
EP0825450B1 EP0825450B1 (fr) 2005-09-28

Family

ID=11404403

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97113891A Expired - Lifetime EP0825450B1 (fr) 1996-08-22 1997-08-12 Dispositif de blindage électromagnétique pour appareils de résonance magnétique nucléaire

Country Status (5)

Country Link
US (1) US5986531A (fr)
EP (1) EP0825450B1 (fr)
DE (1) DE69734269T2 (fr)
ES (1) ES2247611T3 (fr)
IT (1) IT1306601B1 (fr)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0995397A2 (fr) 1998-10-05 2000-04-26 Esaote S.p.A. Appareil de diagnostic et/ou de thérapie, en particulier destiné à l'imagerie par résonance nucléaire magnétique
FR2801384A1 (fr) * 2000-03-30 2001-05-25 Commissariat Energie Atomique Dispositif d'etude d'un objet par resonance magnetique nucleaire, utilisant un champ magnetique statique de faible homogeneite
US6567683B1 (en) 1999-08-27 2003-05-20 Bruker Medical Gmbh Apparatus and method for conducting nuclear magnetic resonance experiments on a member of the body of a big animal
WO2003041576A2 (fr) * 2001-11-12 2003-05-22 Universität Duisburg-Essen Systeme d'electrode pour tomographe a resonance magnetique
WO2006120588A1 (fr) * 2005-05-06 2006-11-16 Koninklijke Philips Electronics, N.V. Protection electromagnetique pour des bobines d'irm a champ eleve
EP1895316A1 (fr) * 2006-09-01 2008-03-05 Esaote S.p.A. Dispositif de protection électromagnétique amovible pour appareils à résonance magnétique nucléaire et procédé de fabrication de celui-ci
WO2014141245A1 (fr) * 2013-03-11 2014-09-18 Aspect Imaging Ltd. Moyens et procédés pour réduire la propagation de l'énergie électromagnétique émanant d'un tunnel magnétique d'un dispositif à résistance magnétique, dans l'environnement extérieur entourant ledit aimant et inversement
EP3143421A4 (fr) * 2014-05-13 2018-04-04 Aspect Imaging Ltd. Gaines de protection et d'immobilisation dotées de capteurs, et procédés permettant de réduire l'effet du mouvement de l'objet pendant le balayage d'irm
US10012711B2 (en) 2013-12-18 2018-07-03 Aspect Imaging Ltd. RF shielding conduit in an MRI closure assembly
US10018692B2 (en) 2013-11-20 2018-07-10 Aspect Imaging Ltd. Shutting assembly for closing an entrance of an MRI device
US10078122B2 (en) 2014-03-09 2018-09-18 Aspect Imaging Ltd. MRI RF shielding jacket
US10101422B2 (en) 2016-12-14 2018-10-16 Aspect Imaging Ltd. Extendable radiofrequency shield for magnetic resonance imaging device
US10132887B2 (en) 2014-03-09 2018-11-20 Aspect Imaging Ltd. MRI thermo-isolating jacket
US10386432B2 (en) 2013-12-18 2019-08-20 Aspect Imaging Ltd. Radiofrequency shielding conduit in a door or a doorframe of a magnetic resonance imaging room
US10401452B2 (en) 2017-04-28 2019-09-03 Aspect Imaging Ltd. System for reduction of a magnetic fringe field of a magnetic resonance imaging device

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1298015B1 (it) * 1997-09-16 1999-12-20 Esaote Spa Lettino in particolare nelle macchine per il rilevamento d'immagine in risonanza magnetica nucleare.
US7529575B2 (en) * 1998-10-05 2009-05-05 Esaote S.P.A. Nuclear magnetic resonance imaging device
US9490063B2 (en) 2003-02-26 2016-11-08 Analogic Corporation Shielded power coupling device
US7868723B2 (en) * 2003-02-26 2011-01-11 Analogic Corporation Power coupling device
US8350655B2 (en) * 2003-02-26 2013-01-08 Analogic Corporation Shielded power coupling device
US9368272B2 (en) 2003-02-26 2016-06-14 Analogic Corporation Shielded power coupling device
ITSV20030033A1 (it) * 2003-09-09 2005-03-10 Esaote Spa Metodo e dispositivo per imaging diagnostico di estremita',
IL158417A0 (en) * 2003-10-15 2004-05-12 Odin Medical Technologies Ltd Integrated radio frequency interference shield
WO2005047915A1 (fr) * 2003-11-12 2005-05-26 Koninklijke Philips Electronics N.V. Systeme d'i.r.m. a bobines de reception rf fixees au boitier
WO2006057701A2 (fr) * 2004-11-24 2006-06-01 Fonar Corporation Accessoire d'immobilisation pour imagerie par resonance magnetique
JP4664797B2 (ja) * 2005-10-13 2011-04-06 ジーイー・メディカル・システムズ・グローバル・テクノロジー・カンパニー・エルエルシー Ｍｒｉ装置
TW200947648A (en) * 2008-05-01 2009-11-16 Advanced Connection Tech Inc Electronic device and method for making the same
US20100157566A1 (en) * 2008-12-19 2010-06-24 Robert Bogursky Electronic shield assembly and methods
US8555578B2 (en) 2011-04-22 2013-10-15 Medtrak Holding Company, Llc Shielded movable door element of a multimodality medical suite
DE102012212574B4 (de) * 2012-07-18 2017-01-12 Siemens Healthcare Gmbh Verfahren zur elektromagnetischen Abschirmung für eine Magnetresonanzanlage sowie entsprechend abgeschirmte Vorrichtung
ITUB20155278A1 (it) * 2015-10-28 2017-04-28 Antonello Sotgiu Apparato di imaging tramite Risonanze Magnetiche (MRI) dedicato all?osservazione ad alta risoluzione dell?occhio umano comprendente magnete ultracompatto, ricevitore ad antenna multipla e tecniche hardware e software per il disaccoppiamento delle antenne e l?annullamento del rumore ambientale. e software per il disaccoppiamento delle antenne e l?annullamento del rumore ambientale.
GB2576579A (en) * 2018-08-24 2020-02-26 Magnetic Shields Ltd Magnetic shield device
EP3899565A2 (fr) * 2018-12-19 2021-10-27 Hyperfine, Inc. Système et procédés de mise à la terre de patients pendant une imagerie par résonance magnétique
CA3156997A1 (fr) 2019-10-08 2021-04-15 Hyperfine Operations, Inc. Systeme et procedes de detection de brouillage electromagnetique chez des patients pendant une imagerie a resonance magnetique
US11500045B1 (en) 2021-07-12 2022-11-15 Zepp, Inc. Shielding of a portable MRI system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4725781A (en) * 1985-03-30 1988-02-16 U.S. Philips Corporation Coil arrangement for nuclear magnetic resonance examinations
DE3807178A1 (de) * 1987-03-06 1988-09-29 Toshiba Kawasaki Kk Magnetresonanz-bildgeraet
EP0364019A1 (fr) * 1988-10-03 1990-04-18 Philips Patentverwaltung GmbH Dispositif d'amortissement de bruit et écran à haute fréquence pour l'ouverture d'examen d'un appareil de tomographie par RM
JPH02203840A (ja) * 1989-02-03 1990-08-13 Hitachi Medical Corp 核磁気共鳴イメージング装置用電磁波シールド構造

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL8203621A (nl) * 1982-09-20 1984-04-16 Philips Nv Kernspintomograaf met faraday kooi.
US4613820A (en) * 1984-04-06 1986-09-23 General Electric Company RF shielded room for NMR imaging system
JPS60242350A (ja) * 1984-05-16 1985-12-02 Sanyo Electric Co Ltd 核磁気共鳴撮像装置
US4920318A (en) * 1985-08-14 1990-04-24 Picker International, Inc. Surface coil system for magnetic resonance imaging
US5050999A (en) * 1990-07-26 1991-09-24 Loon Iii James C Van Open-mesh net bag and method of forming the same
US5735278A (en) * 1996-03-15 1998-04-07 National Research Council Of Canada Surgical procedure with magnetic resonance imaging

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4725781A (en) * 1985-03-30 1988-02-16 U.S. Philips Corporation Coil arrangement for nuclear magnetic resonance examinations
DE3807178A1 (de) * 1987-03-06 1988-09-29 Toshiba Kawasaki Kk Magnetresonanz-bildgeraet
EP0364019A1 (fr) * 1988-10-03 1990-04-18 Philips Patentverwaltung GmbH Dispositif d'amortissement de bruit et écran à haute fréquence pour l'ouverture d'examen d'un appareil de tomographie par RM
JPH02203840A (ja) * 1989-02-03 1990-08-13 Hitachi Medical Corp 核磁気共鳴イメージング装置用電磁波シールド構造

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 14, no. 492 (C-0773), 26 October 1990 (1990-10-26) & JP 02 203840 A (HITACHI MEDICAL CORP), 13 August 1990 (1990-08-13) *

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0995397A2 (fr) 1998-10-05 2000-04-26 Esaote S.p.A. Appareil de diagnostic et/ou de thérapie, en particulier destiné à l'imagerie par résonance nucléaire magnétique
EP0995397A3 (fr) * 1998-10-05 2000-05-03 Esaote S.p.A. Appareil de diagnostic et/ou de thérapie, en particulier destiné à l'imagerie par résonance nucléaire magnétique
EP1004269A1 (fr) * 1998-10-05 2000-05-31 Esaote S.p.A. Table pour patient destinée à être combinée à un dispositif d'imagerie par résonance magnétique
US6801038B2 (en) 1998-10-05 2004-10-05 Esaote S.P.A. Machine for diagnostic and/or therapeutic treatment, particularly a nuclear magnetic resonance imaging machine
US6346814B1 (en) 1998-10-05 2002-02-12 Alessandro Carrozzi Machine for diagnostic and/or therapeutic treatment, particularly a nuclear magnetic resonance imaging machine
US6377830B1 (en) 1998-10-05 2002-04-23 Esaote, S.P.A. Patient table in combination with biomedical apparati like magnetic resonance imaging machine
US6567683B1 (en) 1999-08-27 2003-05-20 Bruker Medical Gmbh Apparatus and method for conducting nuclear magnetic resonance experiments on a member of the body of a big animal
FR2801384A1 (fr) * 2000-03-30 2001-05-25 Commissariat Energie Atomique Dispositif d'etude d'un objet par resonance magnetique nucleaire, utilisant un champ magnetique statique de faible homogeneite
WO2003041576A2 (fr) * 2001-11-12 2003-05-22 Universität Duisburg-Essen Systeme d'electrode pour tomographe a resonance magnetique
WO2003041576A3 (fr) * 2001-11-12 2003-12-31 Univ Duisburg Essen Systeme d'electrode pour tomographe a resonance magnetique
WO2006120588A1 (fr) * 2005-05-06 2006-11-16 Koninklijke Philips Electronics, N.V. Protection electromagnetique pour des bobines d'irm a champ eleve
US7633294B2 (en) 2005-05-06 2009-12-15 Koninklijke Philips Electronics N.V. Electromagnetic shielding for high field MRI coils
CN101171526B (zh) * 2005-05-06 2012-07-18 皇家飞利浦电子股份有限公司 用于高场mri线圈的电磁屏蔽
EP1895316A1 (fr) * 2006-09-01 2008-03-05 Esaote S.p.A. Dispositif de protection électromagnétique amovible pour appareils à résonance magnétique nucléaire et procédé de fabrication de celui-ci
WO2014141245A1 (fr) * 2013-03-11 2014-09-18 Aspect Imaging Ltd. Moyens et procédés pour réduire la propagation de l'énergie électromagnétique émanant d'un tunnel magnétique d'un dispositif à résistance magnétique, dans l'environnement extérieur entourant ledit aimant et inversement
US9470769B2 (en) 2013-03-11 2016-10-18 Aspect Imaging, Ltd. Means and methods for reducing the electromagnetic energy propagation from an MRD's magnet-bore to the outer environment surrounding said magnet, and vice versa
JP2016509948A (ja) * 2013-03-11 2016-04-04 アスペクト イメージング リミテッド Ｍｒｄの磁石ボアから当該磁石の周囲の外部環境への及びその逆の電磁エネルギー伝播を低減するための手段及び方法
US10018692B2 (en) 2013-11-20 2018-07-10 Aspect Imaging Ltd. Shutting assembly for closing an entrance of an MRI device
US10495704B2 (en) 2013-11-20 2019-12-03 Aspect Imaging Ltd. Shutting assembly for closing an entrance of an MRI device
US10012711B2 (en) 2013-12-18 2018-07-03 Aspect Imaging Ltd. RF shielding conduit in an MRI closure assembly
US10386432B2 (en) 2013-12-18 2019-08-20 Aspect Imaging Ltd. Radiofrequency shielding conduit in a door or a doorframe of a magnetic resonance imaging room
US11774532B2 (en) 2013-12-18 2023-10-03 Aspect Imaging Ltd. Rf shielding conduit in an mri closure assembly
US10078122B2 (en) 2014-03-09 2018-09-18 Aspect Imaging Ltd. MRI RF shielding jacket
US10132887B2 (en) 2014-03-09 2018-11-20 Aspect Imaging Ltd. MRI thermo-isolating jacket
US11002809B2 (en) 2014-05-13 2021-05-11 Aspect Imaging Ltd. Protective and immobilizing sleeves with sensors, and methods for reducing the effect of object movement during MRI scanning
EP3143421A4 (fr) * 2014-05-13 2018-04-04 Aspect Imaging Ltd. Gaines de protection et d'immobilisation dotées de capteurs, et procédés permettant de réduire l'effet du mouvement de l'objet pendant le balayage d'irm
US10101422B2 (en) 2016-12-14 2018-10-16 Aspect Imaging Ltd. Extendable radiofrequency shield for magnetic resonance imaging device
US11029378B2 (en) 2016-12-14 2021-06-08 Aspect Imaging Ltd. Extendable radiofrequency shield for magnetic resonance imaging device
US10976393B2 (en) 2017-04-28 2021-04-13 Aspect Imaging Ltd. System for reduction of a magnetic fringe field of a magnetic resonance imaging device
US10401452B2 (en) 2017-04-28 2019-09-03 Aspect Imaging Ltd. System for reduction of a magnetic fringe field of a magnetic resonance imaging device

Also Published As

Publication number Publication date
DE69734269T2 (de) 2006-07-27
ES2247611T3 (es) 2006-03-01
ITRM960591A0 (fr) 1996-08-22
DE69734269D1 (de) 2005-11-03
ITRM960591A1 (it) 1998-02-22
EP0825450B1 (fr) 2005-09-28
EP0825450A3 (fr) 1999-12-29
IT1306601B1 (it) 2001-06-18
US5986531A (en) 1999-11-16

Similar Documents

Publication Publication Date Title
EP0825450B1 (fr) Dispositif de blindage électromagnétique pour appareils de résonance magnétique nucléaire
EP1895316B1 (fr) Dispositif de protection électromagnétique amovible pour appareils à résonance magnétique nucléaire et procédé de fabrication de celui-ci
Bohning et al. Echoplanar BOLD fMRI of brain activation induced by concurrent transcranial magnetic stimulation
US5159929A (en) Insulated rf shield
Wessinger et al. Tonotopy in human auditory cortex examined with functional magnetic resonance imaging
US4608991A (en) Method for in-vivo NMR measurements in the human breast to screen for small breast cancer in an otherwise healthy breast
EP1903935B1 (fr) Appareils d'apport et d'enregistrement de signaux électrophysiologiques pendant une irm
CN101171526B (zh) 用于高场mri线圈的电磁屏蔽
US20040088012A1 (en) Implantable stimulation device with isolating system for minimizing magnetic induction
US5602557A (en) Mammography antenna arrangement for NMR examinations of a female breast
Damji et al. RF interference suppression in a cardiac synchronization system operating in a high magnetic field NMR imaging system
CA2902730C (fr) Moyens et procedes pour reduire la propagation de l'energie electromagnetique emanant d'un tunnel magnetique d'un dispositif a resistance magnetique, dans l'environnement exterieur entourant ledit aimant et inversement
EP0364061B1 (fr) Bobine de surface élargie et formée pour l'imagerie à résonance magnétique présentant un rapport signal sur bruit modifié
US20200085405A1 (en) Ultrasonic device for detecting the heartbeat of a patient
CN112924912A (zh) 磁共振装置
Klimek et al. A discussion of nuclear magnetic resonance (NMR) relaxation time of tumors in terms of their interpretation as self-organizing dissipative structures, and of their study in vivo by NMR zeugmatographic imaging
US20170052234A1 (en) Size-adjustable protecting and immobilizing sleeves for mri devices
JPH01303139A (ja) 磁気共鳴イメージング装置
US11500045B1 (en) Shielding of a portable MRI system
Brazdeikis et al. Non-invasive assessment of the heart function in unshielded clinical environment by SQUID gradiometry
Sanchez et al. Flexible 32-Channel 13C MRI Head Array: An EEG-Lookalike Design Approach
US20220334202A1 (en) Contoured radio frequency coil assemblies for a magnetic resonance system
WO2015173817A2 (fr) Gaines de protection et d'immobilisation dotées de capteurs, et procédés permettant de réduire l'effet du mouvement de l'objet pendant le balayage d'irm
Stevens et al. Energy coupling between RF electric fields and conductive wires: image artifacts and heating
Ballon et al. Rapid three-dimensional whole-body diffusion-weighted echo planar magnetic resonance imaging of metastatic neoplasia

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE ES FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17P Request for examination filed

Effective date: 20000620

AKX Designation fees paid

Free format text: DE ES FR GB IT

17Q First examination report despatched

Effective date: 20040423

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB IT

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REF Corresponds to:

Ref document number: 69734269

Country of ref document: DE

Date of ref document: 20051103

Kind code of ref document: P

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: ESAOTE S.P.A.

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2247611

Country of ref document: ES

Kind code of ref document: T3

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20060629

REG Reference to a national code

Ref country code: FR

Ref legal event code: CA

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20120730

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20120910

Year of fee payment: 16

Ref country code: ES

Payment date: 20120731

Year of fee payment: 16

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20130812

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20140430

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20130812

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20130902

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20140908

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20130813

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20160721

Year of fee payment: 20

Ref country code: DE

Payment date: 20160725

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69734269

Country of ref document: DE